GLYCEROLYSIS OF UREA AS AMMONIA SOURCE FOR MULTI-COMPONENT REACTIONS

The reaction of glycerol with urea to form glycerol carbonate GC (glycerine carbonate or 4-hydroxymethyl-2-oxo-1,3-dioxolane) is mostly reported in the literature since glycerol carbonate has excellent properties such as low toxicity, biodegradability and a high boiling point which make it a very attractive for a variety chemical of applications.1 One of the most validate reaction mechanism of glycerolysis of urea involves a direct attack by urea to glycerol to form GC and ammonia as by-product obtained by decomposition of urea.2 The aim of this study is the exploitation of the glycerolysis process as an ammonia source to promote a domino reaction on the same plant, consuming ammonia obtained from glycerolysis. The process choosed for the ammonia exploitation was the Hantzsch reaction, one of the main way to obtain dihydropyridines (DHPs), a class of heterocyclic systems with a remarkable pharmacological activity.3 Benzaldehyde and ethyl acetoacetatewere was selected as the most representative reactants for optimizing Hantzsch reaction conditions.